Operation CHARM: Car repair manuals for everyone.

Ignition Timing Control System

Ignition Timing Control System:





CIRCUIT OPERATION
The ignition timing is controlled by the ECU to help maintain the best A/F mixture under all operating conditions.
The ECU uses several sensors to calculate the amount of timing based on a map stored in its memory. The ECU varies the timing during:
1. Starting
2. Warm up
3. Idle
4. Hot engine operation
5. Acceleration
6. Low battery voltage

Power Transistor And Ignition Coil:





POWER TRANSISTOR
The power transistor is a voltage amplifier that allows the signal sent from the ECU to activate the primary circuit in the ignition coil. This induces high voltage in the secondary windings of the ignition coil, providing spark to the distributor cap and plugs.